The long term objective is to provide an inexpensive device that rapidly measures the body density (in air) of adults so that a quantitative degree of obesity (body fat-fraction) may be deduced. Such routine measurements should result in improved weight control programs with consequent reduction in the health risks associated with hypertension, cardiovascular disease, cancer, diabetes, and many other disorders. The proposed device measures body volume acoustically using the Helmholtz resonator principle with excitation by a thin air jet. The effects of temperature and humidity on the measurement are reduced by employing a second high frequency resonator. The device relies only on the measurement of acoustic signal frequency - not amplitude. Its simplicity, ruggedness and ease of use should make the measurement of fat fraction with the acoustic volumeter as standard as the patients weight. PROPOSED COMMERCIAL APPLICATION: There is a good market a device that can quickly and accurately measure body volume, and derive body density and composition. Potential buyers range from individuals and health/fitness centers to universities and hospitals.